Well, Markdown is designed to look good in raw text.. it’s one of the design directives
Readability, however, is emphasized above all else. A Markdown-formatted document should be publishable as-is, as plain text, without looking like it’s been marked up with tags or formatting instructions.
Problem is we have nasty BBcode in there. I’d rather convert BBCode to text, personally, rather than playing a game of “telephone” where we go Markdown → HTML → text